Do I Need a Prime Lens in My Bag?
What Does "Prime" Mean?
Prime lens is short for primary focal length or fixed focal length when talking about the lenses for your camera. Whilst having less versatility over a zoom lens, the benefits are that primes are generally:
...in both glass and image quality due to having less moving parts.
Another benefit with a good prime lens is maximum aperture. Check out a bunch of prime lenses at Amazon.
Many zoom lenses only go as far as f2.8 as their maximum opening. Whereas lenses such as the 50mm can go as wide as f1.4. This allows more light to enter the camera giving faster shutter speeds in low light. It also creates a magical depth of field as it this image shot with the stunning EF 50mm f1.4 lens from Canon.
Owning a prime depends entirely on personal preference, budget and what type of photography is your "thing". A prime lens could be:
...and so on. Not so long ago, there was no such thing as a zoom lens and all we had were prime or fixed lenses.
Zoom Lens vs Prime Lens
People tend to use zoom lenses nowadays for convenience (or laziness), plus standard (and mostly crappy) zooms are sold with cameras as a kit lens. You can have a wide focal range on just one zoom lens meaning you have less to carry around.
Imagine a time before zooms were introduced when you had nothing but prime lenses and you covered a wide range. You may have carried up to 10 lenses with you…heavy! now just 3 lenses could cover the focal plane from 16mm to 400mm (up to 800mm if you also have a 2x converter)!
I would always suggest that you have at least one prime/fixed lens in your kit, and if you only have one, you could make it a macro lens too! Go for anything between 50mm and 135mm as any of these are great for portrait shots and will give noticeably better quality. For wildlife or sports photography, a zoom lens may suit you more as with the fast action it is easier to zoom in and out than to run about!